Electric steering compass



L. RELLSTAB ELECTRIC STEERING iCOMPASS Filed Nov. 20. 1920 2 Sma ts-Sheet 1 512,051 L. RIELLSTAB 4 ELECTRIC STEERING COMPASS Filed Nov. 20. 1920 2 Sheets-Shoot 2 Patented a. m, 1924.

UNITED STATES- PATENT OFFICE.

LUDWIG BELLSTAB, OF ZEIST, NETHERLANDS, ASSIGNOR- TO SIEMENS & E ALSKE, AK-

TIENGESELLSOHAFT, OF SIEMENSSTADT, NEAR BERLIN, GERMANY, A GERMAN CORPORATION.

ELECTRIC STEERING COMPASS.

Application filled November 20, 1920. Serial No. 425,584.

To all whom it may concern:

Be it. known that I, 'LUDWIG RELLSTAB, a citizen of the German Empire, residing at Zeist, Netherlands, have invented certain new and useful Improvements in Electric Steering Compasses (for which I have filed applications in Germany, July 11, 1918, Patent No. 342,297; Denmark, July- 8, 1919;

Holland, July 11, 1919; Norway July 28, 1919; and in En land, October 23, 1919, Patent No. 134,226 of which the following is -a specification.

My "nvention refers to electric compasses, and itsparticular object is to provide a device for indicating the deviations of 'a ship from the course in water ways having cables fed with electric currents disposed therein.

My invention substantially consists in an arrangement, whereby the induction our- .20' rents resulting from the conductors submerged in the water are amplified by aid of auxiliary devices inserted in the circuit of the receiver loops on both sides of the ship,

whereupon they are rectified and translated by means of direct current'indicators. These latter may be constructed in any suitable manner, for instance, as shown in the drawings, in the form of simple needle galvanometers or as a movingcoil system common to the loops on both sides of the ship, such instrument, as is well known, indicating the quotient of the currents.

The auxiliary devices for amplifyin the induction current may consist in amp 'fier tubes of a well-known kind, such as Lieben relays, while for rectification for instance the same kind of relays or crystal detectors may be used. Owing to their merely indirect connection with the indicating instruments these devices can easily be arranged outside the wheel house so that in this room merely the indicating instruments are disposed, such instruments being preferably located within the same wall box with their pointers crossing each other.

In the drawings afiixed to this specification and forming part thereof the preferred form of a steering system according to the present invention is illustrated in a purely diagrammatic manner.

In these drawings:

Fig. 1 shows an entire steering coil system in which two galvanometers, one for each side of the ship, are cooperatively used as indicating meansby crossing their indicators;

Figs. 2 and 3 show difl'erent connections of the four receiving loops with the indicating device, each figure showing the shi inclined and in parallel to the pilot cablb or cables; and

Fig. 4 shows a moving coil system used in place of a pair of galvanom'eters for producing an indication.

Referringto Fig. 1, A and B are loops disposed on the port and starboard sides, respectively, of a ship, said loops bein influenced by the induction currents res ting from a single cable lying in the middle (Fig. 3) or from two cables lying on the sides of the water way, as shown in Fig. 2.

U and U are trans-formers inserted in the circuits of loops A and B, res ectivel said transformers leading to amp ifier tu es V and V, respectively. The induction currents amplified thereby are then rectified by crystal detectors D and D respectively and conducted to needle galvanometers Gr and Gr, respectively. The two galvanometers are combined so as to form a single instrument for instance of the size of an ordinary voltmeter with their pointers crossed, as shown for G G, in Fig. 1 in full. lines for zero position when no current is received by the loops. .At equal deflection of both pointers in opposite directions the crossing point of the pointers ascends vertically on the center line m of the device, whereas at a greater deflection of one or the other galvanometer'the crossing point will deviate laterally, as shown by dotted lines, the more so,:-the greater the difference between the deflections of the two instruments. In the position shown in the drawing in dotted lines the pointer of the galvanometer G, has a greater deflection and in consequence thereof the crossing point K- lies on the right hand side of the center linem of the box containing both galvanometers, it being indicated thereby that the shi has deviated to starboard from the mid le of the water way and has approached the starboardcable 1 ing in the water way (Fig. 2).

If one suc indicating device. is provided I 1 I for the bow. and; for thestern, the two dei- I vices i may: be I disposed together; svithin :1 I I commonbonandarranged-to havclheirccnterlinesim.incommon, which-line may": be made permanently visible as: a pilot: line: I

, representing the cable, so: that the parallel; zor angular position of: the line, connecting the; two crossing. points :K, of their I inch: 1 I gcato'rs; relatively to the pilot line I m allows i to: ascertain the equal i or different deviation I I I I v I 13: thebowior sternzfromthe-course- This =I:;.-. form is showni in: Fig; 2 which I il l ustrates the vessel inclined to the; imaginary; I I center :linebctween the two cables (3,6, and .15 i which also shows the vessel in I parallel ;to, I I I but laterally of: this: line; I I The: imaginarycenter: line is indicated :on the apparatusmounted ;on the vessel by the dash-dot line i m, m.. I' The line K, K .ineach case indicates e direction; in which the vessel is angu-z rly inclined to; the center line between i the l I two cahlesq The. galnanometer;coils G .fi .I: I I I I I I L I I .indicated 1, lfGiSllGWI-liill 2 only: 1-; -ina general-way'in connectionwith: their. I I as g respective: receiving coils A B the, actual I I f I cu ts b i gthe same I as shown- I Fig. 1: withregardtocoilsG G, I I f::. I I )Fig; ;3 shows a f vessel; wo; positions; I I i guided by one. single cable In this: cascg :however,. the dash-dot linei a; drawn f I system represents; the center-line of the ship; f I 3' whereas the line K, :K- represents the ipo. I I i 5 :tionof the cable,- so that out of the angular i I relation between: the :two lines the I angular I 1 position ofthevessel relatively to the cable may be ascertained. In this case, however, the stern receiving coils A B are connected with the bow indicating coils G G the bow receiving coils A, B with the stern indicating coils G G This cross connection in this case is necessary to obtain correct indication. However, no matter what the line m, m represents, whether the center line of the vessel or the cable, it always represents a pilot line by means of which the angular position of this vessel relatively to the pilot cable may be directly read off. Therefore, when I refer in the annexed claims to a pilot line, this line may represent any of the lines m, m shown in the drawings, so long as this line runs through the longitudinal center of the indicating instrumenqso that the indications of the latter' occur symmetrically to the right or left of this line.

The amplifier tubes V V are permanentlyfed with direct current as long as the operation of the device is required, so that on one of them getting damaged the closed circuit current which also influences the galvanometcrs is interrupted and the pointer of the instrument in question is no more deflected. This is so conspicuous that it isbound to be observed immediately.

' thmngh 3 the g t i inalf center; of the coil: 1 I

ring and rectifying the :alternatin induced said loop 1 said; cable current I I I and an:indicating instrument having a pilot 1 I 3 I i 2 I i 1 line; i extending I through: the: f longitudinal center of said Indicating instrument and I I Instead of needle galvanometer pair's G 1 I I 6,; and G G zone.: ma employ: as well, I I I i I moving coil systems: well: known in the art, I I as:illustrated'foninstancci n-Fig. 4:; Such if: L 70 i [1,36 respectively for eacl1'-loop;A:and .B, the-' coils carbhcing mountedso that-theirf centerplanes of I winding symmetrically I I I cross each, other; 111 i alinementi with the I intersection iline' :of these two :pl'anes I and I :frecly rotatable on this line asan axis; a I .I :thircl coil c -is disposed, which tends to ad I I I i ust itself angular-lyrelatively to the fixed I a system is provided with a statioi'rary coil tromotive: forces generated by the currents means connected with said loop circuits for directly visibly indicating by the joint action of said loop currents the position of the vessel relatively to the cable.

2. In radio pilot cable systems for vessels, having a pilot cable disposed on the fairway bottom and supplied with alternating current, in combination at least one pair of receiver loops, one loop disposed on each side of the vessel to be piloted, the circuit of each loop including means for amplifying and rectifying the alternating currents induced in said loop by said cable current and an instrument of the galvanometer type. having a pilot line extending'through the longitudinal center of said indicating instrument, said instrument being connected with both of said loop circuits for directly visibly indicating by the joint action of said loop currents the position of the vessel relatively to the cable.

3. In radio pilot cable systems for vessels, having a pilot cable disposed onthe fairway bottom and supplied with alternating current, in combination at least one pair of receiver loops, One loop disposed on each side of the vessel to be piloted, the circuitof each loop including means for amplifying and rectifying the alternating currents I coils in accordance with: the resultant elec- E I I 1 I 2 flowing; in the two? fixed? coils I a; b, thereby f I I I I f ;indicating-theqnotient of the cnrrents ofathe I 1 1 5 two fixed coils; I Anzindicatori d is: fixedto f I :coil- :6; which I cooperates with a scale a and I i I t thus: gives. the, same: indications which are hbtained lay-the crossing points K of the two I 1 I I cooperating: :galvanometeri pairs in Figs; I I i I l; In radiorpilot cable systems for? vessels; 5 I havinga pilot cable disposed on the fair- I I 1 f way; bottom and supplied: with I alternating I 1 I current, in I combination as least; :one pair of receiver; loops, one loop Edisposed on each :sideiof the vessel to be: piloted, the circuit: '0' each. loop; inclitdinq means ifor am plify-r i f I I g 1 currients: I

induced in said loop by said cable current and an instrument of the galvanometer type, having two coils disposed side by side and each connected with one of said loops each coil having a pointer crossing the pointer of the other coil, said instrument also having a pilot line extending througlrthe longitudinal center of said indicating instrument,

wthe crossing point of said pointers varying ,current, in combination two pairs of receiver loops, one pair disposed near the bow, the other pair near the stern of the vessel, one loop of each pair being disposed on each side of the vessel, the circuit of each loop of each pair including means for amplifying and rectifying the alternating current induced in said loop by said cable current, and an indicating device having a pilot line extending through the longitudinal center of said indicating instrument and means connected with the loop circuits of each pair, and adapted to directly visibly indicate by the joint action of its loop currents the position of the vessel portion, at which said loop pair is located, relatively to said pilot line, the position points given by said two pairs relatively to said line indicating the .side, and

angular relation of the entire vessel to said pilot cable.

5. In radio pilot cable systems for vessels having a pilot cable dis osed on the fairway bottom and supplied with alternating current in combination two pair of receiver loops, one pair disposed near the bow, the other pair near the stern of the vessel, one loop of each pair being disposed on each side of the vessel, the circuit of each loop of each pair including means for amplifying and rectifying the alternating current induced in said loop by said cablecurrent, and an indicating device comprising an instrument of the galvanometer type for each loop pair, having two coils disposed side by each connected with one of said loops, each coil having a pointer, crossing the pointer of the other coil, a pilot 'line on said indicating device running between said two instruments and located midway between the two coils of each instrument, the crossing point of the pointers of each instrument varying laterally of said line in accordance with the difference between the currents induced in its individualloops, caused by the deviation of the vessel portion at which said loop pair is located from its course set by the cable, the position points given by the pointer of said two pairs relatively to said line indicating the angular relation of the entire vessel to said pilot'cable. In testimony whereof I aflix my signature.

vLUDW'IGr RELLSTAB. 

